Conventionally, printed circuit boards (PCB) functioning as component carriers comprise a plurality of bores which form vias for generating an electrical connection to an electrical component. Additional, the bores are used to provide a heat transfer to the environment in order to reduce the risk of overheating. Around 30% of bores (vias) which may be formed by laser drilling are used only for heat transfer. Also there is a method using mechanically drilled holes for forming PTH (plated through hole) by using a resin-plug in to fill up the empty space.
Each component carrier usually comprises a plurality of vias (bores), for example more than thousand. Hence, it is necessary to provide a high-speed bore forming process in order to manufacture the component carrier in a short manufacturing time. Moreover, very small manufacturing tolerances for the size of the bores are allowed in order to provide a proper connectivity. Hence, the high-speed drilling process must not be only fast but must be also very accurate.
Conventional bores need to have a small diameter such that connection pads are kept small and the bores have enough space in the component carrier. However, small sized bores also have less capacity for the heat transfer.